Noninvasive oximetry optical sensor including disposable and reusable elements

ABSTRACT

A pulse oximetry sensor includes reusable and disposable elements. To assemble the sensor, members of the reusable element are mated with assembly mechanisms of the disposable element. The assembled sensor provides independent movement between the reusable and disposable elements.

RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 13/585,669, filed Aug. 14, 2012, entitled “Noninvasive OximetryOptical Sensor Including Disposable and Reusable Elements,” now U.S.Pat. No. ______, which is a continuation of U.S. patent application Ser.No. 11/754,972, filed May 29, 2007, entitled “Noninvasive OximetryOptical Sensor Including Disposable and Reusable Elements,” now U.S.Pat. No. 8,244,325, which is a continuation of U.S. patent applicationSer. No. 11/172,587, filed Jun. 30, 2005, entitled “Optical SensorIncluding Disposable and Reusable Elements,” now U.S. Pat. No.7,225,007, which is a continuation of U.S. patent application Ser. No.10/351,645, filed Jan. 24, 2003, entitled “Optical Sensor IncludingDisposable and Reusable Elements,” now U.S. Pat. No. 6,920,345, andclaims priority benefit under 35 U.S.C. §120 to the same. The presentapplication incorporates the foregoing disclosures herein by reference.

FIELD OF THE INVENTION

The present invention relates to the field of sensors that measureoxygen content in a patient's blood. More specifically, the inventionrelates to a sensor that assembles reusable and disposable elementsand/or allows longitudinal displacement between the reusable anddisposable elements.

BACKGROUND OF THE INVENTION

Early detection of low blood oxygen is important in a wide variety ofmedical applications, and oximetry was developed to study and tomeasure, among other things, the oxygen status of blood. One type ofoximetry, pulse oximetry, employs a sensor attached to a patient inorder to output a signal indicative of a physiological parameter of thepatient, such as, for example, the patient's blood oxygen saturation.

A pulse oximeter sensor generally uses a number of sensor components,such as one or more energy emission devices like red and infrared LEDemitters, and an energy detection device like a photodiode detector. Thesensor is generally attached to a measurement site such as a patient'sfinger, toe, ear, forehead, foot, hand, heel or the like, using anattachment mechanism such as a disposable tape, reusable housing, Velcrostrap, or the like. The attachment mechanism positions the emitter anddetector in proximity to the measurement site, such that the emitterprojects energy into the blood vessels and capillaries of themeasurement site, and the photodiode detector then detects theattenuated energy. The emitted energy can be light or other forms ofenergy. The detector communicates a signal indicative of the detectedattenuated energy to a signal processing device such as an oximeter. Theoximeter generally calculates, among other things, one or morephysiological parameters of the measurement site.

In sensors where the detector detects emissions through the measurementsite, it is generally desirable to position the detector opposite theemitter around the measurement site, such as, for example, above andbelow a finger. However, sensors are produced in a limited number ofsizes and shape configurations, while patients have, for example,fingers and toes of many different sizes and shapes.

In addition, the attachment mechanism and the electronic components of asensor are generally curved around a measurement site in a mannerdetrimental to one or more elements of the sensor. For example, theattachment mechanism generally wraps around the measurement site at anapproximate “inner circle” having a first radius, while the electroniccomponents such as the flexible circuits are generally fixedly attachedto the attachment mechanism. Accordingly, the electronic components canform an approximate “outer circle” having a second radius unequal to thefirst radius. However, because the attachment mechanism generally doesnot move independently with respect to the electrical components,attachment of the sensor to the measurement site can exert forces on theelectrical components, such as, for example, exerting forces which tryto lengthen, or longitudinally stretch the electrical components toaccount for an increased radius thereof. The forced stretching candamage the electrical components of a flexible circuit, such as theconductive traces.

SUMMARY OF THE INVENTION

Based on the foregoing, embodiments of the present invention include asensor comprising reusable and disposable sensor elements that permitlongitudinal displacement with respect to one another when the sensor isattached to a measurement site. For example, in one embodiment thesensor includes a reusable element and a disposable element configuredto receive the reusable element in a releasable attachment assemblyproviding longitudinal displacement between the disposable and reusableelements. The longitudinal displacement advantageously allows the sensorelements to self-adjust with respect to one another during attachment tothe measurement site. The self-adjustment or independent movementadvantageously reduces the forces caused by longitudinal stretching,thereby reducing damage to the reusable element.

One aspect of the invention relates to an optical probe including areusable element and a disposable element that can be attached togetherby placing or snapping protrusions on one element into apertures andreceiving slots on the other element. For example, the reusable elementcan be fitted with protrusions made of plastic, and the disposableelement can be fitted with detents or tabs, which include apertures orreceiving slots. The reusable element attaches to the disposable elementby inserting, or snapping, the protrusions into the apertures and thereceiving slots of the tabs. When assembled, at least some of theprotrusions are slidable within the receiving slots to independentlymove along a longitudinal axis of the sensor, thereby providing somelongitudinal decoupling between the reusable element and the disposableelement.

Another aspect of the invention relates to a sensor with a reusableelement and a disposable element where the reusable element is made of aflexible or pliable material and includes one or more neck sections. Thedisposable element includes two straps, each of which is configured toreceive a neck section. The reusable element and the disposable elementare attached together by placing the neck sections within the straps. Inone embodiment, the neck sections include a long neck section and ashort neck section. The long neck section has a sufficient length toallow longitudinal movement of the reusable element within the strap,thus permitting movement of the reusable element with respect to thedisposable element.

Another aspect of the invention relates to a sensor with a reusableelement and a disposable element where the reusable element is securedby guides or tabs affixed to the disposable element. The guides allowlimited longitudinal motion of the reusable element and thereby allowthe reusable element to flex independently of the disposable element asthe device is positioned on a patient.

Another aspect of the invention relates to a sensor with a reusableelement and a disposable element where the reusable element is encasedin a protective cover. In one embodiment, the protective cover is madeof a pliable material and prevents any sharp edges from scratching orpoking a patient or caregiver. The protective cover also advantageouslyprevents damage to the reusable element that could occur from dirt,dust, liquids, or other elements of the environment.

Yet another aspect of the invention relates to a sensor with a reusableelement and a disposable element where the disposable element includes abreakable element. After an approximate predetermined number of safeuses, the breakable element breaks and the disposable element isrendered inoperable or otherwise indicates its over use.

For purposes of summarizing the invention, certain aspects, advantagesand novel features of the invention have been described herein. Ofcourse, it is to be understood that not necessarily all such aspects,advantages or features will be embodied in any particular embodiment ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A general architecture that implements the various features of theinvention will now be described with reference to the drawings. Thedrawings and the associated descriptions are provided to illustrateembodiments of the invention and not to limit the scope of theinvention. The drawings are not necessarily drawn to scale. Throughoutthe drawings, reference numbers are re-used to indicate correspondencebetween referenced elements. In addition, the first digit of eachreference number indicates the figure in which the element firstappears.

FIG. 1 illustrates a perspective view of an embodiment of an unassembledsensor that includes reusable and disposable elements.

FIG. 2 illustrates a perspective view of tabs of the disposable elementof FIG. 1.

FIG. 3A illustrates a cross-sectional view of another embodiment of tabsof a disposable element.

FIG. 3B illustrates a cross-sectional view of yet another embodiment oftabs of a disposable element.

FIG. 4A illustrates a cross-sectional view of the two tabs of FIG. 2,adhesively attached to the disposable element.

FIG. 4B illustrates a cross-sectional view of the two tabs of FIG. 2,attached between layers of the disposable element.

FIG. 5 illustrates a top view of the disposable element of FIG. 1,including an information element and breakable conductor.

FIG. 6 illustrates a top view of another embodiment of an assembledsensor that includes reusable and disposable elements.

FIGS. 7A and 7B illustrate simplified cross-sectional views of anembodiment of a strap of the disposable element of FIG. 6.

FIG. 8 illustrates an exploded view of a disposable element according toanother embodiment of an optical sensor.

FIG. 9 illustrates a perspective view of the disposable element of FIG.8.

FIG. 10 illustrates a perspective view of an embodiment of a reusableelement according to an embodiment of the optical sensor of FIG. 8.

FIG. 11 illustrates a perspective view of a flex circuit of the reusableelement of FIG. 10.

FIG. 12 illustrates a perspective view of the assembled optical sensorincluding the disposable element of FIG. 8 and the reusable element ofFIG. 10.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates an embodiment of a sensor 100. The sensor 100includes a reusable element 110 and a disposable element 120. Accordingto one embodiment, the reusable element 110 generally includes thosecomponents of the sensor 100 that are more expensive, such as, forexample, one or more energy emitters, one or more energy detectors, oneor more breakable conductors, one or more information elements, some orall of the same, or the like. In addition, the reusable element 110includes an assembly mechanism generally shaped to mate with acorresponding component of the disposable element 120, as will bedisclosed in greater detail below.

The disposable element 120 generally includes those components of thesensor 100 that are less expensive, such as, for example, face tape,bandages, or other mechanisms for removably attaching the reusableelement 110 to a measurement site. Moreover, the disposable element 120includes a mating assembly mechanism generally shaped to mate withassembly mechanism of the reusable element 110, thereby attaching thereusable element 110 to the disposable element 120 in a manner thatprovides for at least some self adjustment or displacement between theelements.

When the disposable element 120 attaches the reusable element 110 totissue of a measurement site, a signal processing device, such as anoximeter, activates the energy emitters to transmit light energy intothe tissue. The tissue attenuates the light energy, which is thendetected by the detector. A signal indicative of the detected lightenergy is then generally forwarded back to the signal processing devicefor determination of one or more physiological parameters of the tissue,such as, for example, oxygen saturation, pulse rate, or the like.

A skilled artisan will recognize from the disclosure herein that thereare many combinations of differing shapes and circuit configurations forthe reusable and disposable elements, 110 and 120, respectively, suchas, for example, those disclosed in U.S. Pat. No. 6,377,829, and U.S.patent application Ser. No. 10/020,664, filed on Dec. 11, 2001, both ofwhich are hereby incorporated by reference.

As shown in the exemplary embodiment of FIG. 1, the reusable element 110can include one or more energy emitters 112, an energy detector 114, andan electrical connector 116 electrically communicating with the emitters112 and the detector 114 through a flexible circuit. According to oneembodiment, the flexible circuit comprises material of a generallyflexible or pliable construction.

The reusable element 110 also includes the foregoing assembly mechanism,such as, for example, the one or more protrusions 118. According to oneembodiment, the protrusions 118 comprise approximatelycylindrical-shaped or tab-shaped extensions made of plastic or otherdurable materials. FIG. 1, shows the reusable element 110 including fourprotrusions 118, two opposing protrusions proximate a front portion andextending in opposite generally horizontal directions, and two opposingprotrusions proximate a back portion and extending in opposite generallyhorizontal directions. According to one embodiment, the protrusions 118roughly align with one or more of the electronic components of thesensor 100. As described below, the protrusions 118 each advantageouslymate with the mating assembly mechanism of the disposable element 120 ina manner providing for at least some displacement of the reusableelement 110 with respect to the disposable element 120, thereby avoidingdamage or harmful wear of the reusable element 110.

FIG. 1 also shows the flexible circuit including an optical barrier,such as, for example, an aperture or gap 119 to reduce light energy fromtraveling from the emitter 112 to the detector 114 without first passingthrough tissue at the measurement site (i.e., light piping). A skilledartisan will recognize from the disclosure herein that the gap 119 couldbe replaced with opaque materials, protrusions, pads, tabs, or otherlight blocking mechanisms.

Although disclosed with reference to preferred embodiments, a skilledartisan will recognize from the disclosure herein, a number of otherembodiments of the reusable element 110. For example, one or more of theemitters 112 or the detector 114 can be located on the disposableelement 120. Moreover, the flexible circuit may comprise plastic,electric wires, polyester substrates, or the like.

FIG. 1 also shows the disposable element 120. According to anembodiment, the disposable elemental 120 generally comprises a base 130comprising a face tapestock material similar to that of an adhesivebandage shaped to position the reusable elemental proximate themeasurement site. The face tape can include an adhesive covered baseprotected by one or more conveniently shaped release liners or layers.Although illustrated in a conventional elongated surface with opposingwings style shape, an artisan will recognize from the disclosure hereinthat the tape may comprise virtually any shape, including thosedisclosed in U.S. patent application Ser. No. 10/020,664, referencedabove. Moreover, the disposable elemental 120 may comprise a Velcrostrap, a foam wrap, a reusable plastic housing or the like.

The disposable element 120 also includes the assembly mechanism,illustrated as tabs 122 and 124. Each of the tabs 122 include anaperture 132, while each of the tabs 124 include a receiving slot 134.In one embodiment, the apertures 132 and the receiving slots 134 havesufficient depth to receive the protrusions 118. In other embodiments,the apertures 132 and receiving slots 134 extend through the tabs 122and 124. As shown in FIG. 1, the tabs 122 and 124 are shaped toremovably receive the reusable elemental 110. For example, the tabs 122and 124 can include sloped surfaces that cause the tabs 122 and 124 todisplace outwardly during assembly of the sensor 100. For example, whenthe reusable element 110 is properly positioned within the tabs 122 and124, the tabs 122 and 124 snap inwardly over the reusable element 110such that the protrusions 118 are within the apertures 132 and thereceiving slots 134. When assembled, vertical and horizontal movementbetween the reusable and disposable elements, 110 and 120 respectively,is substantially prevented by the relationship between the tabs 122 and124, the apertures 132, the slots 134 and the protrusions 118. However,the slots 134 provide for displacement between elements alonglongitudinal axis A when the disposable portion 120 is wrapped around ameasurement site by allowing the protrusions 118 to slide back and forthwithin the slots 134. Thus, the assembly mechanisms of the reusable anddisposable elements, 110 and 120, provide independent movement betweenthe elements, thereby allowing self-adjustment of the sensor 100 to thediffering radiuses of each element. Such construction advantageouslyreduces the harmful stressing effects applied to components of thereusable element 110.

FIG. 1 also shows that a gap 142, slot or aperture, or otherwisetransparent area can be included on the disposable element 120 to permitlight from the emitter 112 to travel through the disposable element 120to the tissue of the measurement site. Moreover, another gap 144 can beincluded on the disposable element 120 to permit attenuated light fromthe measurement site tissue to travel through the disposable element 120to the detector 114. In another embodiment, some or all of the base 130of the disposable element 120 is made of a transparent material, and thegaps 142 and 144 can be omitted.

A skilled artisan will recognize from the disclosure herein that thetabs 122 and 124 of the disposable element 120 can be implemented in awide variety of embodiments. For example, an embodiment can include eachof the tabs 122 and 124 having a receiving slot 134 while anotherembodiment can include each of the tabs 122 and 124 having an aperture132.

FIG. 2 illustrates a perspective view of the tabs 124 including thereceiving slots 134. As disclosed, the tabs 124 can be shaped to includea sloped surface 220 configured to displace a ledge or catch 230 duringsensor assembly. For example, the sloped surface 220 displaces outwardlywhen protrusions 118 are pressed in the direction of the arrow C. Thenwhen the reusable element 110 is properly positioned, the protrusions118 snap into the receiving slots 134 and the catch 230 snaps over a topsurface of the reusable element 110.

The receiving slots 134 are longer than the cross sectional width of theprotrusions 118 so that the protrusions 118 can move within thereceiving slots 134 to different positions along the longitudinal axis Aof the disposable element 120. The apertures 132, on the other hand, aresized to allow protrusions 118 to be located within the apertures 132but to prevent substantial movement along the longitudinal axis A of thedisposable element 120, thus ensuring proper positioning of the sensorelements, with respect to the tissue and one another.

In an embodiment, the reusable element 110 and the disposable element120 are assembled into the sensor 100 when the protrusions 118 aresnapped into the apertures 132 and the receiving slots 134 of the tabs122 and 124. The assembled sensor 100 is then attached to a measurementsite, through, for example, application of the adhesive covered side ofthe face tape to tissue at the measurement site. During application, theprotrusions 118 within the receiving slots 134 move along the receivingslot 134, while the protrusions 118 remain positioned within theaperture 132. This type of flexibility advantageously reduces thestretching force placed on conventional reusable elements.

FIG. 2 also shows receiving slots 134 as grooves in the walls 240 of thetabs 124, where the grooves do not extend all the way through the walls240. In other embodiments, the receiving slots 134 can be open slotsthat extend through the walls 240. Likewise, the aperture 132 can bestraightforward depressions, or punch through holes.

FIG. 3A illustrates a cross-sectional view of tabs 300 of anotherembodiment of a disposable element, such as disposable element 120 ofFIG. 1. The tabs 300 include the receiving slot 134 for receiving theprotrusions 118, but does not include the sloped surface 220 or thecatch 230 of FIG. 2. Thus, the reusable element 110 is assembled relyingon the interaction described in the foregoing between the protrusions118 and the apertures 132 and the slots 134.

FIG. 3B illustrates a cross-sectional view of tabs 310 of anotherembodiment of a disposable element, such as the disposable element ofFIG. 1. The tabs 310 include the sloped surface 220 and the catch 230,but do not include the receiving slot 134 or aperture 132. Thus, thesensor 100 is assembled relying on the interaction between the catch 230and the surface of the reusable element 110.

FIG. 4A illustrates a cross-sectional view of the tabs 124 of FIG. 1adhesively attached to the disposable element 120, according to anembodiment. In FIG. 4A, the tabs 124 are attached to the base 130 byadhesive. In a preferred arrangement, the tabs 124 share a commonsubstrate 310, and an adhesive is applied between the substrate 310 andthe base 130 to attach the tabs 124 to the disposable element 120.

FIG. 4B illustrates a cross-sectional view of the tabs 124 of FIG. 1attached between layers of the disposable element 120 of FIG. 1,according to another embodiment. In FIG. 4B, the tabs 124 are attachedbetween two layers 410 and 420 of the base 130. In a preferredarrangement, the two tabs 124 share a common substrate 310, and thesubstrate 310 is sandwiched between the layers 410 and 420.

A skilled artisan will recognize from the disclosure herein that theembodiments disclosed with reference to FIGS. 3 and 4 can be applied toone or both sets of the tabs 122 and 124. Moreover, a skilled artisanwill recognize from the disclosure herein that the protrusions 118 canbe attached to the reusable element 110 in a number of ways, such as,for example, attached by adhesive to the reusable element 110,manufactured as integral parts of the reusable element 110, sandwichedbetween a top layer and a bottom layer of the reusable element 110, orthe like.

FIG. 5 illustrates a top view of the disposable element of FIG. 1,including an information element 510, contacts 520, and a breakableconductor 530, according to yet another embodiment. The contacts 520 canelectrically connect with contacts on the flexible circuit of thereusable element 120, thereby adding the information element 510 and/orthe breakable conductor 530 into the electric circuit of the sensor 100.As is understood in the art, the information element 510 can provide anindication of the sensor or patient type, operating characteristics orthe like, or that the sensor 100 is from an authorized supplier. In anembodiment, the information element 510 is a resistive element made bydepositing a conductive ink trace having a predetermined length andwidth. The information element 510 is disposed between contacts 520,which can also be implemented with conductive ink. As an artisan willrecognize from the disclosure herein, many type of information elementscan be included, such as, for example, passive or active elements,accessible memory elements, or the like.

The breakable conductor 530 is configured to break after a predeterminednumber of safe uses, thus providing quality control to ensure that thedisposable element 120 is not over used. Various embodiments ofinformation element 510, contacts 520, and breakable conductor 530 canbe found in U.S. Pat. No. 6,377,829.

FIG. 6 illustrates a top view of an assembled sensor 600 that includesreusable and disposable elements, according to another embodiment. Asshown in FIG. 6, the sensor 600 includes a reusable element 610 and adisposable element 620. The disposable element 620 includes straps 630which position the reusable element 610 as described below. As shown inFIG. 6, the reusable element 610 can be similar to the reusable element110 of the foregoing embodiments, generally including, for example, themore expensive components of the sensor 600. Moreover, disposableelement 620 can be similar to the disposable element 120 of theforegoing embodiments, generally including for example, a disposabletape. The disposable tape can be virtually any suitable shape, and isshown in FIG. 6 in a generally “L” shaped configuration.

FIG. 6 also shows the reusable portion 610 including an extended narrowneck or notch 635 and a neck or notch 640, each narrower in width thanthe general width of the reusable element 610. The straps 630 attachedto the disposable element 620 extend over the necks 635 and 640 toposition the reusable element 610 with respect to and proximate thedisposable element 620. The straps 630 provide for longitudinal movementbetween the elements of the sensor 600 similar to that disclosed in theforegoing.

FIG. 7A illustrates a simplified cross-sectional view of one of thestraps 630 of the disposable element 620 of FIG. 6, according to anembodiment. The strap 630 may comprise a hook-and-loop device such asVelcro. The strap 630 may alternatively be an integral part of thestructure of the disposable element 620. According to an embodiment, thestrap 630 includes blocks 720 forming a gap 710 therebetween. As shownin FIG. 7A, an embodiment of the strap 620 can be removed from thedisposable element 620 to permit the neck 630 of the reusable element610 to be placed within the gap 710, as show in FIG. 7B an artisan willalso recognize from the disclosure herein that the pliable material ofthe reusable portion 610 can alternatively or concurrently be compressedtogether and guided through attached straps 630.

According to one embodiment, the gap 710 is as wide or slightly widerthan the necks 635 and 640, but narrower than other adjacent portions ofthe reusable element 610. Therefore, once placed in the gaps 710 andattached to the disposable element 620, the reusable element 610 can bemoved along its longitudinal axis along the arrows A and B (FIG. 7B),but only to the extent that the necks 635 and 640 remain in the gaps710.

In one embodiment shown in FIG. 6, the reusable element 610 includes therelatively “long” neck 635 shown near the top of the figure and arelatively “short” neck 640 shown near the bottom of the figure. Oncethe two necks 635 and 640 are placed within the straps 650, the longneck 635 allows the reusable element 610 to be moved along alongitudinal axis of the disposable element 120. In contrast, the shortneck 640 prevents substantial movement along the longitudinal axis.Thus, similar to embodiments disclosed in the foregoing, the sensor 600allows the neck 630 to self adjust during application to a measurementsite, thereby avoiding damaging the reusable element 610.

FIG. 8 illustrates an exploded view of a disposable element 810according to another embodiment of an optical sensor. The disposableelement 810 includes a top layer 812, at least one attachment mechanism,tab, or positioning guide 814, and an adhesive, preferably transparent,tape layer 816. FIG. 8 shows tabs 814 positioned in a back-to-back oropposing manner, as will be described in greater detail below.

FIG. 8 shows the top layer 812 as a generally L shaped tape or otherpliable substrate including a first side 822 and a second side 824,although an artisan will recognize from the disclosure herein that thevirtually any shape can be used which provides attachment to tissue of apatient. According to an embodiment, the first side 822 includes abreakable element 826, such as the conductive trace disclosed in U.S.Pat. No. 6,377,829, discussed in the foregoing. The breakable element826 is included into the electrical circuit of the optical sensorthrough electrical leads or contacts 830 configured to electricallycommunicate with contacts of a reusable element of the optical sensor.Moreover, the first side 822 of the top layer 812 can optionally includean optical barrier layer 831, such as a layer of material opaque orsubstantially opaque to light. The optical barrier layer 831 isgenerally designed to help prevent ambient light or light piping frominterfering with the optical signals before or after they are passedthrough the tissue of the patient. In one embodiment, the barrier layer831 comprises conductive trace material similar to that of the breakableelement 826.

According to an embodiment, the top layer 812 also includes a pluralityof apertures 832, which when the optical sensor is assembled, acceptportions of the tabs 814 in a manner designed to provide properplacement, positioning, and support of the tabs 814. However, an artisanwill recognize from the disclosure herein that top layer 812 may use inkoutlines combined with adhesive, or the like to help an assemblerproperly place and support the tabs 814 on the first side 822 of the toplayer 812.

Each tab 814 includes a base 836, a signal aperture 838, and grooves orslots 840. The base 836 connects and supports each of two raised sidemembers forming a generally U shaped structure. The signal apertures 838comprise holes through which a properly positioned sensor element canemit or detect optical signals, and the raised side members each includethe slot 840, similar to the grooves 134 of the tabs 124 of FIG. 1.However, unlike FIG. 1, an embodiment of each of the slots 840 opensfrom one side of the raised side member, extends along the side member,and ends before the other side of the raised side member. Thus, the slot840 accepts a protrusion or the like from an insertion side, and allowsthe protrusion to slide within the slot 840 to the end thereof,proximate a blocked side. Moreover, according to one embodiment, theblocked sides of the tabs 814 approximately adjacently oppose oneanother, such that protrusions inserted into the insertion sides, are atone point blocked from sliding closer than a predetermined distance fromone another by the blocked sides.

According to one embodiment, the tape layer 816 comprises a transparenttape or other substrate layer. The tape layer 816 has a first side 846and a second side 848. When assembled, the first side 846 adheres to thetop layer 812 and sandwiches the tabs 814 therebetween. The second side848 includes an adhesive, hook-and-loop, similar or combinationstructure configured to secure the disposable element 810 to tissue of apatient.

FIG. 8 also shows the disposable element 810 including a cable connector850. The cable connector 850 generally provides for connection of thedisposable element 810 to the remainder of a sensor, such as, forexample, the reusable elements. According to the exemplary embodiment,the cable connector 850 comprises a plastic plate 852 including matingportions 854, such as, for example, raised pliable detents that eachincluding a catch. However, an artisan will recognize from thedisclosure herein any suitable mating mechanism can be used to connectthe disposable element 810, including virtually any mechanical-typemating mechanism, adhesives, hook-and-loop materials, combinations, orthe like.

When the disposable element 810 is assembled as shown in FIG. 9, thebases 836 of the tabs 814 and the plate 852 communicate with the secondside 824 of the top layer 812 and first side 846 of the tape layer 816such that the bases 836 of the tabs 814 and the plate 852 are secured inposition between the top layer 812 and the tape layer 816. The raisedside members of the tabs 814 extend through the plurality of apertures832 in the top layer 812, thereby aligning the signal apertures 838 withapertures in the top layer 812. Moreover, as shown in the illustratedembodiment, the mating portions 854 of the cable connector 850 extendabove the top layer 812.

FIG. 10 shows a perspective view of an embodiment of a reusable element1000. The reusable element 1000 preferably includes a protective coveror coating 1004 covering a plurality of electronic sensor elements 1005and a plurality of protrusions 1006. The reusable element 1000 alsoincludes a cable connection housing 1008, and cord or cable 1010.According to one embodiment, the protective cover 1004 comprises a softmaterial, such as a pliable rubber, plastic or the like, whichpreferably encapsulates and protects the electronic sensor elements 1005from damage and advantageously protects caregivers and patients fromsharp corners often associated with the reusable element 1000, such as,for example, the protrusions 1006 or the sensor elements 1005.

The protrusions 1006 extend from opposing sides of the reusable element1000 in generally horizontal and opposing directions. To assemble theoptical sensor, the protrusions are aligned with the outside-facinginsertion side of each of the slots 840 of the disposable element 810,shown in FIG. 8, and are slid toward one another on each side. As can beseen in FIG. 12, an embodiment of the assembled sensor includes one ormore of the protrusions 1006 abutting the blocked side of one pair ofthe slots 810, while the other protrusions 1006 are proximate theblocked side of the other pair of slots 810, thereby allowing thereusable element 1000 to self adjust and avoid the detrimentalstretching forces caused from application to a measurement site.

FIG. 10 also shows the cable connection housing 1008 including insertionslots 1012 configured to receive and mate with the mating portions 854of the cable connector 850 shown in FIG. 8. When mated, the cableconnection housing 1008 provides electrical contact between theelectrical leads 830 of the disposable element 810 and the sensorcircuitry.

FIG. 11 illustrates a perspective view of portions of the electronicsensor elements 1005 of the reusable element 1100 without the protectivecover or coating 1004. The elements 1005 include one or more energyemitters 1102, such as one or more LEDs, an energy detector 1104, suchas a photodetector, electrically connected to a connector 1106 through aflexible circuit 1108. The connector 1106 is configured to electricallycommunicate with the leads 830 of the disposable element 810 when thesensor is assembled. Moreover, the connector 1106 is configured toelectrically attach the conductive traces of the flexible circuit 1108to the conductors of the cable 1010.

FIG. 12 shows a perspective view of an assembled sensor 1200. The sensor1200 includes the reusable element 1000, including the disposableelement 810 connected to the connection housing 1008 through the matingportions 854 of the cable connector 850, such that the breakable element826 is part of the electrical circuitry of the sensor. In oneembodiment, the sensor is inoperative or otherwise provides anindication of overuse or misuse when the breakable element 826 is brokenor otherwise becomes an open circuit.

As disclosed, when connected to the disposable element 810, theprotrusions 1006 have a limited range of motion within the tabs 814,thereby giving the reusable element 1000 a limited range of longitudinalmotion independent of the disposable element 810. As described withother embodiments, this longitudinal motion allows the disposableelement 810 and the reusable element 1000 to flex independently as thesensor 1200 is attached to tissue of a user, such as a finger, toe, ear,or the like, thereby avoiding damage or unnecessarily harmful wear ofthe reusable element 1000. Also, this limited range of motion ensures atleast approximate proper alignment of various sensor components.

After use, as with embodiments described above, the disposable element810 is removed and discarded, while the reusable element 812 can besterilized and reused.

Although the foregoing invention has been described in terms of certainpreferred embodiments, other embodiments will be apparent to those ofordinary skill in the art from the disclosure herein. For example,although the above sections describe a reusable element fitted withprotrusions or necks and a disposable element fitted with apertures andreceiving slots or straps, the embodiments can be reversed having, forexample, the reusable element fitted with the apertures, receivingslots, or straps, and with the disposable element fitted with theprotrusions or necks.

Additionally, other combinations, omissions, substitutions andmodifications will be apparent to the skilled artisan in view of thedisclosure herein. Accordingly, the present invention is not intended tobe limited by the reaction of the preferred embodiments, but is to bedefined by reference to the appended claims.

What is claimed is:
 1. A noninvasive optical oximetry sensor including areusable portion and a disposable portion, the sensor comprising: saidreusable portion including: a flex circuit, a light source, one or moredetectors configured to detect light from said light source afterattenuation by tissue of a patient at a measurement site and configuredoutput said signals responsive to said detected light, a plurality ofconductors proximate said flex circuit, some of said conductorscommunicating with said light source and others of said conductorscommunicating with said one or more detectors, and a protective coatingencasing at least said light source, said one or more detectors and atleast some of said conductors and some of said flex circuit; saiddisposable portion including a positioning mechanism configured toposition said light source proximate said measurement site; andmechanical elements, a first one or more elements proximate saidreusable portion and configured to mate with a second one or moreelements proximate said disposable portion, wherein when mated and whensaid light source is positioned proximate said measurement site, some ofsaid elements self-adjust to lock the reusable portion in position withrespect to the disposable portion.
 2. The noninvasive optical oximetrysensor of claim 1 wherein said protective coating comprises a flexibleprotective coating.
 3. The noninvasive optical oximetry sensor of claim2 wherein the flexible protective coating comprise a rubber or plasticmaterial.
 4. A multi-layered noninvasive optical medical sensorcomprising: an attachment layer configured to position sensor componentsproximate a measurement site on a patient; a nonflexible layer includingmechanical structures configured to mate with other mechanicalstructures, wherein when said attachment layer positions said sensorcomponents, said mated structures move to preclude separation and whensaid attachment layer is not positioning said sensor components, saidmated structures move to allow separation; and a flexible layerincluding a light source and a detector, said light source configured toemit light, said detector configured to detect said light afterattenuation by body tissue at said measurement site.
 5. Themulti-layered noninvasive optical medical sensor of claim 4, whereinsaid flexible layer includes a reusable portion.
 6. The multi-layerednoninvasive optical medical sensor of claim 5, wherein said flexiblelayer includes a protective coating.
 7. The multi-layered noninvasiveoptical medical sensor of claim 4, wherein said attachment layerincludes a disposable portion.
 8. The multi-layered noninvasive opticalmedical sensor of claim 4, wherein said mechanical structures includetabs and matable slots for said tabs.
 9. The multi-layered noninvasiveoptical medical sensor of claim 8, wherein some of said tabs and matableslots combine to preclude vertical movement of said tabs within saidslots when said attachment layer positions said sensor components.